The filmmaker’s family said he died while listening to the score of The Quiet Man, one of his favourite films, in the company of his wife and daughter.
Night Of The Living Dead was credited with defining the trope of zombie movie when it was created by Mr Romero in 1968, on a shoestring budget of around $100,000.
His undead creatures stumbled after their human prey, transforming them into zombies in turn by biting into their flesh, and perishing only after a shot to the head.
Ten years later Romero made Dawn Of The Dead, described by film critic Roger Ebert as “violent, brutal and appalling,” as well as “savagely merciless in its satiric view of American consumer society”.
Mr Romero’s movies were about much more than just shuffling zombies: they took on racism, mall culture, class divides and militarism. In Dawn of The Dead, for example, the human characters seek safety from zombies in a shopping centre, but much of the action takes place as they turn on each other.
Mr Romero’s casting of Duane Jones, a black actor, as the lead role in Night Of The Living Dead was also considered a breakthrough and the movie is considered an important handling of race in the US.
He told the Associated Press in 2008 the zombies could represent anything and that “the stories are about how people fail to respond in the proper way”.
News of Mr Romero’s death was met with sadness in the film world.
Steven King, whose novel The Dark Half was adapted by Mr Romero, called him his “favourite collaborator”, adding “there will never be another like you”.
Mr Romero died after a short battle with lung cancer. The news of his death was announced by his manager Chris Roe.